Book Image

Applied Supervised Learning with R

By : Karthik Ramasubramanian, Jojo Moolayil
Book Image

Applied Supervised Learning with R

By: Karthik Ramasubramanian, Jojo Moolayil

Overview of this book

R provides excellent visualization features that are essential for exploring data before using it in automated learning. Applied Supervised Learning with R helps you cover the complete process of employing R to develop applications using supervised machine learning algorithms for your business needs. The book starts by helping you develop your analytical thinking to create a problem statement using business inputs and domain research. You will then learn different evaluation metrics that compare various algorithms, and later progress to using these metrics to select the best algorithm for your problem. After finalizing the algorithm you want to use, you will study the hyperparameter optimization technique to fine-tune your set of optimal parameters. The book demonstrates how you can add different regularization terms to avoid overfitting your model. By the end of this book, you will have gained the advanced skills you need for modeling a supervised machine learning algorithm that precisely fulfills your business needs.
Table of Contents (12 chapters)
Applied Supervised Learning with R
Preface

Exploratory Data Analysis (EDA)


Building regression models requires an in-depth analysis of the patterns and relationship between target and input variables. The Beijing dataset provides a magnitude of different environmental factors that may affect the PM2.5 levels in the atmosphere.

Exercise 42: Exploring the Time Series Views of PM2.5, DEWP, TEMP, and PRES variables of the Beijing PM2.5 Dataset

In this exercise, we will visualize the pm2.5, DEWP, TEMP, and PRES variables in a time series plot and observe any patterns that may emerge over the years in these variables.

Perform the following steps to complete the exercise:

  1. Import all the required libraries in the system:

    library(dplyr)
    library(lubridate)
    library(tidyr)
    library(grid)
    library(ggplot2)
  2. Next, transform year, month, and hour into datetime using the lubridate package function named ymd_h:

    PM25$datetime <- with(PM25, ymd_h(sprintf('%04d%02d%02d%02d', year, month, day,hour)))
  3. Plot the PM2.5, TEMP, DEWP, and PRES for all the years using...